Reactivities governed by a single metal atom M in mixed-metal highnuclearity clusters having [Ru5M(C)] core (M = Co, Rh, Pd): Site-nonselective, site-selective, and chemo-selective variations in the SO2-trapping reactions

The SO2 substitution for a CO ligand of the hexa-nuclear carbonyl complexes having Ru5M(C) type carbido-metal core, [PPN][Ru5Co(C)(CO)16] (2), [PPN][Ru5Rh(C)(CO)16] (3), and Ru5Pd(C)(CO)16 (4), is dramatically affected by the kind of metal atom M: 2 (M = Co) is reactive but not site-selective, 3 (M = Rh) is reactive and site-selective, whereas 4 (M = Pd) is not reactive at all even though 4 can easily react with PPh3 to give the substitution products.